Composition for sizing yarns



UNITED STATES PATENT OFFICE GOIWPOSITION FOR SIZING YARNS James T. Power, Wilmington, Del., and Ernest G. Almy, Tamaqua, Pa., assignors to Atlas Powder Company, Wilmington, Del., a corporation of I Delaware No Drawing. Application October 9, 1934, Serial No. 747,648

1 Claim. (Cl. 134 -23) This invention relates to compositions for 512- cause the sized yarn, if subjected to highly humid ing yarns, threads, filaments, etc., hereinafter conditions will absorb an excess of moisture and referred to generically as yarns. The invention will lose its good running properties. However, has for its object the provision of a sizing matelimited amounts of moisture are desirable for rial which, when applied to the yarns, possesses good running properties. 5 a high degree of softness and pliability and Now we have found that sorbitol is an excel- Which, at the same time, has an extremely slight lent softening agent for sizing compositions. It susceptibility to changes in properties under has the distinct advantage that while it absorbs varying conditions of atmospheric humidity. approximately as much moisture as does glyc- Further objects and advantages of the invention erine in atmospheres of low relative humidity yet will be set forth in the following description and in atmospheres of high relative humidity it abappended claim. sorbs much less moisture than does-glycerine.

A compound, to be suitable for sizing yarns, Furthermore, sorbitol produces a greater softenmust be satisfactory for weaving, must be capaing effect than does gly r AS a r the bio of being easily removed in finishing and must Sizer is able to impart to the sized yarn a much be readily absorbed by the yarn. For example, greater softness and pliability and at the same in the weaving of rayon it is essential that the time be free from the dlfiiculties experienced sizing material bind the filaments comprising the heretofore due to varying humidity conditions. yarn and uniformly coat the yarn with a film re- Furthermore, sorbitol is exceedingly soluble in sistant to chafing. The film of si'zingmaterial water and can be washed from the yarn without 20 must be sufficiently soft and pliable to insure having to resorttc vigorous treatment. We have good running conditions and must at the Some also found that sorbitol is readily absorbed by time possess toughness and elasticity to with-' yarns, even more so than is glycerine. A suitable stand strain of the various operations in weaving. sizing material for rayon warp is illustrated in The term "yarn as used in this specification and the following example. 25 in the appended claim relatesto the material in Example I a strand form and prior to weaving. In this form, I the several strands are coated by the binder to A very satisfa t ry p p size oontainin prevent damage to the yarns by the chafing inorbitol is produced by soaking 28.7 lbs. of a cident to the passage of the yarns through fabribinder, such as gelatin, in 57.8 lbs. of cold water. eating machines such as weaving machines and The mixture is heated to 140 F. to render the the like. mixture fluid and thus facilitate mixing. To this i The sizing used in weaving is usually removed mixture is added with thorough mixing, a warm from the fabric prior to the steps of dyeing and yrup (temperature 140 F.) containing 10.2 lbs. finishing. It is therefore essential that the sizing or sorbitol. 1.3 lbs. glu s and 2 1138- Wateron be removable from the woven goods. Owing to coolin h mixture 86135 W a firm j y- In O the relatively low wet strength of artificial silk der to prep e ba for Sizing rayon w ps his or rayon, the sizing must be removable therefrom jelly is dissolved in warm water. A suitable prowith minimum treatment. portion is 100 lbs. of the preparedsize to '75 gal- 40 In view of the high speed at which the yarns ions of water.

pass through the fabricating machines in modem In compounding such a prepared size, we may p t c it s necessary that e Sizing material use for the sorbitol-glucose syrup a crude sorbitol be readily absorbed by the yarn and it must, after syrup, such as is obtained by reduction of glucose. being applied to the yarn, dry quickly so that the It may contain in addition to sorbitol, moisture threads will not adhere to one another. and glucose, small amounts of ash and organic \In sizing materials, especially those containing impurities. I latin as a ind r. glycerine has found pp a- We have found that sorbitol is compatible with tion as a softening agent. However, glycerine other softening agents used in sizing'composihas certain properties which make its use in such tions. In some cases it may be desirable to subsizing composition not wholly satisfactory. Prinstitute other softening agents such as sulfonated. 5o cipal among these is its great tendency to absorb oils or saponified oils, for a part of the sorbitol. an excess of moisture, especially under conditions A formula for a sizing bath which we have found of high humidity. Consequently, the slzer is not to be satisfactory and in which sulfonated castor able to take advantage of the full softening-effect oil is substituted for part of the sorbitol is shown ofglycerine in gelatin sizing compositions beln Example 11. u

Gil

. waxes.

fect solution. The sorbitol and sulfonated castor oil are dissolved therein and an additional amount of water is added to adjust the volume to 50 .gallons. Furthermore, it should be pointed out that part or all of the gelatin may be replaced by other binding materials such as starch, dextrin, gum arabic and other soluble gums and In Example III we illustrate a formula for a sizing bath in which a part of the gelatin is substituted by soluble starch and British gum.

Example III Pounds Gelatin 4.8 Soluble starch 4.0 British gum 11.2 Sorbltol 4.6 Sulfonated castor oil V 4.0

The gelatin, soluble starch and British gum are soaked together in about 30 gallons of water. The mixture is heated to 140 F. to effect solution. The sorbitol and sulfonated castor oil are dissolved therein and an additional amount of water is' added to adjust the volume to 50 galions.

A suitable sizing material for rayon filling yarns is illustrated in the following example:

Example IV I Pounds Gelatin 4.7 Sorbltol 20.0 Water to make 50 gallons.

The gelatin is soaked in about 30 gallons of cold water. The mixture is heated to 140 F.

- to eflect solution, the sorbitol dissolved in the mixture and water added to bring the total volume to 50 gallons. The sorbitol employed in the above examples and in other sizing mixtures need not be chemically pure sorbitol but may be a syrup such as is obtained by the reduction of glucose, containing besides sorbitol small amounts of 'moisture, ash, sugar and other impurities. We find it convenient to employ a syrup containing 15% or 20% of moisture to facilitate the mixing.

While we have shown specific compositions of sizing materials containing sorbitol we wish it to be understood that we do not limit ourselves to the concentrations mentioned therein nor to the ingredients mentioned, other than sorbitol. It is to be understood, likewise, that the incorporation or mixing of sorbitol with any of the other ingredients prior to introduction into the sizing bath comes within the purview of this invention. Those skilled in the art will readily appreciate that other ingredients and-different concentrations and different orders of mixing may be employed for special purposes without departing from the spirit of this invention which relates to sizing compositions containing sorbitol.

While we have indicated the desirable characteristics of sorbitol as a substitute for glycerine in the softening of sizing compositions, we wish to make it clear that mixtures of sorbitol and glycerine may be employed and are within the pur view of the invention.

Having described our invention, what we claim 1s:

A warp sizing for rayon yarns comprising an aqueous mixture containing substantially from 3.9 to 4.6 per cent by weight ofawater-miscible binder selected from the group consisting of gelatin, soluble starch, dextrin and gum arable and substantially from 1 to 1.4 per cent by weight of a softening agent consisting essentially of sorbitol, said sorbitol acting as a softener for 

